Function at the Level of C4

What Motor Function is Consistent with C4?
  • The nerve root of C4 runs between vertebrae C3 and C4. 
  • Motor function includes:
    • head control
    • neck movement (paraspinal muscles, CN XI, trapezius muscle)
    • ability to breathe possible (diaphragm)
    • mouth control (facial muscles)
    • no upper extremity movement 
What Sensory Function is Consistent with C4?
  • C4 provides sensation across the shoulders.
Assessment of C4 Motor Function
Assess and document motor function using motor scale from 0-5.
  • Evaluate ability to shrug shoulders 
  • Evaluate ability to shrug against examiner resistance.
Assessment of C4 Sensory Function
  • Test one side of shoulders, then test same spot on opposite side
  • Always apply the same amount of pressure to each side
  • Ask patient to compare sensation on side A to side B
  • Conceal test from the patient
    • Light touch:
      • use wisp of cotton or tissue; touch shoulders on either side and assess sensation
    • Sharp or temperture touch:
      • use safety pin, cap of pen or ice cube (do not use needle); assess shoulder sensation on either side
Expected Outcome
  • use of mouth stick for typing, page turning, switch devices
  • swallowing
  • may have problems maintaining spontaneous ventilation

Brenda Morgan
Clinical Educator, CCTC
May 11, 2001

Barr, M, and Kiernan, J. (1993). The Human Nervous System: An Anatomical Viewpoint. Philadelphia: Lippincott. pp 84-85.

Keppler, J. (1987). Acute spinal cord injury. Critical Care Clinics. July. 3:3. pp. 638-641.

Netter, F. (1989). Atlas of Human Anatomy. New Jersey: Novartis.

Waxman, S. (1996). Correlative Neuroanatomy. 23rd Ed.  Stamford: Lange. pp 46-52, 352-355, 370.


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Last Updated March 31, 2009 | © 2007, LHSC, London Ontario Canada